Pressure regulator valve



May 2s, 1946. J E, DUBE 2,401,144

PRESSURE 4REGULATOR VALVE Filed Jan. 2, 1941 ExPAA/s/w VALVE V 'PatentedMay 1946 i *i c UNITED STATES PATENT OFFICE 2,401,144 j PRESSUREREGULATOR vALvE mm E. nube, clayton. Mal-mimito su vain Gompny.Maplewood, Mo., a, corporation of me l Appuuun'ranuny z, 1941,' No.:72,708

, e clams. (osez-121) The present invention is an improvement in apressure regulator valve, and more particularly in a valve of this typecontrolled by a thermostatic` device or-pressure-fresponsive' means.

In general, the mechanism includes a main valve adapted to be employedin a pipe line such as a'line'between the evaporator' and the compressor.in a refrigeration system. This main Y valve has a member attached toit movable in response to pressure changes. The pressure side of thismember is connected through a pilot valve .tol a point the pressure ofwhich is to be employed to control the main valve. 'I'he pilot valve isdesigned to be controlled by pressure in the line acting against acounterpressure 'that is a resultant of a predetermined pressureresistance and a pressure resistance due to temperature conditions. Y

Among the objects of the invention are to provide a regulator responsiveto temperature and pressure combined, to provide a regulator responfVsive to variations in load conditions producing temperature changes, aswell as pressure changes; and to provide a regulator establishing acritical pressure for its operation with means automatically to varythat critical pressure upon tempera' ture changes. v

Specific objects include provision of a pressure responsive devicehaving means producing a counterpressure, and temperature responsivemeans to vary the counterpressure. With particular regard to arefrigeration system, an object of the invention is to produce apressure-responsive control acting by eilecting a counterpressure, andtemperature responsive means to increase this collnterpressure upon"decrease of temperature at--the expansion coils. Even more particularly,it is an object to provide a control system for use in maintaining aminimum pressure in the evaporator. and to reduce that minimum pressureupon rise of 4temperature of a chosen point in which a temperatureresponsive member is located. A particular object is to provide in sucha device a means to adjust the sensitivity of external pressure ortemperature responsive means, such as the bellows. in changing thepressure setting of the regulator, such that the amount of change inpressure -per degree of temperature change may be nicely controlled.

Furtherobjects include providing the foregoing mechanism with a singlesealing-moving element with no sealing moving Joints; to provide readyand sensitive adjustments 'for the pressure and temperature means: and`to provide such 30 pleSSOl'.

other properties as appear from the following description. Y In thedrawing: Fig. 1 is a more or less schematic view ofthe pertinentportions ofV a refrigeration system with the valve of the presentinvention therein;l-

Fig. 2 is a vertical medial section of the valve; Fig.'3 is a horizontalsection taken on the line 3-3 toward the upper Dart of Fig. 2 showing anadjustment means Fig. 4 is an enlarged view of the pilot valve and itsseat; .f

Fig. 5 is a plan view of the fulci'um support for the pilot valveoperating mechanism; and,

Fig. 6 is a plan view of the' pilot valve operating lever. ,p l

The device may be illustrated inY connection with' a refrigerationsystem, though its principles I are obviously broader.

The pertinent portions of the refrigeration system include an evaporatorcoil .I0 adapted to cool the contents of a container Il, which may be abrine tank. The container has an inlet pipe I2 and an outlet pipe I2.The outlet pipe is pro-l vided with a T I4 for a purpose to bedescribed.

The coil I0 has a line I5 connected to an inlet /Side Is of a main`valve generany designated at I1. From the outlet side Il of this valvethere extends a suction pipe I9 leading to the com- The system includesthe usual compressor, condenser and expansion valve, as indicated, thelast being attached to the coil I0. The pilot valve is generallyindicated at 20. A pilot tube 2| leads from a point vin the pipe I!suitable for pressure/control. A pressure gauge 22 may be employed inthis pilot line if desired.

The main valve I1 includes a valve body 25 with a circular valveseat-receiving portion 26 in the usual partition Wall between the inletII-and the outlet I8. A cylindrical lter 2'I is disposed in the inletportion of the valve body.

A valve seat member 28, circular in shape, engages snugly within thevalve seat-receiving portion 28, and extends upwardly through a circularopening provided inthe upper wall of the valve body 2l. This valve seatportion has a,

' plurality of ports 2l and 30 adapted to register with the outletportion of the valve housing. The valve seat member 2l has below theports a circular valve seat Il surrounding a valve pasf `sage 22 whichis thus disposed between the inlet and outlet portions of the valve bodymember 2l.

A valve 23 vengages the valve seat II to close thereagainst and vto .cutof! communication through the valve. vThis valve has a central re-V poseto .be described.

striction plug fitting fairly closely within the passage 32, which istapered and permits only small iiow through the passage until the valveopens clamped between the top of the valve body 2t and a cylindricalhousing 38 employed for a pur- The fastening means, which usually aremachine screws, are not shown.

The housing 38 constitutes a cylinder receiving` a well-fitting skirtedpiston di therein. The skirt of this piston extends down over the valverod Sill which engages against the underside of the piston head.

The valve rod 3d. is maintained against the piston by a coil spring d2that surrounds the tubular guide 8! and engages at one end against thetop portion of the member 23. It also engages at its upper end against acupped washer d3 held to a maximum upper position on the valve rod by awasher 44 secured in a neck on the rod. 'Ihe spring 42, therefore, urgesthe valve 33 toward its closed position, correspondingly urgingthepiston di upwardly. The spring is relatively light, and is designedmerely to close the valve upon equalizing of pressure above and belowthe piston,

The cylinder 99 has a passage d5 extending across the cylinder head andmeeting a vertical passage 66 leading to the piston. A vertical passagelllextends from the inlet side I6 of the valve housing 25 to the flange31. 'A continuation 4E of the passage 61 is formed in one portion of theflange 91 but there is no corresponding continuation diametricallyopposite. Within the cylinder there is a further continuation 9extending to the passage 45. As shown in the drawing. the member 28 hasbeen turned so that the portda is out of registry with the two passages5,1 and 9 which` are thereby cut oil. Upon turning the member 28 180,the port 48 may be made to register with the passages 41 and t9. Thismay be used when it is desired to bypass the pilot valve and operate themain valve directly from inlet pressure.

The cylinder head has a bleeder port SB therethrough.

threaded into the upper part of the outlet passage 5B and is adapted tobe engaged by the diaphragm under pressure of a pressure member orbuffer plate i.

i The valve, comprising the diaphragm d@ acted on by the buffer plateSi, thus controls communication between the inlet` and the outlet pilotlines. The diaphragm sealso the space above it from that below it.

The bufferplate @i is attached to a stem @2, to the upper end of whichis secured a head @t urged into seating position by a coil spring Eidthat in turn engages another head 6E threaded about anadjusting screw 55secured in a casing El. The screw S6 is rotatably mounted in the casingEl, but has a shoulder limiting its upward movement under the influenceof the spring. A cap @E is threaded onto the casing 'l to enclose andprotect a squared head 99 on the upper part o the screw 65. A pin 1li issecured on the underside of the casing 61 and passes through the head 65to permit axial movement thereof along the screw 6%, but to preventrotation.

Rotation of the screw 9B by means of a tool applied to the head 99 willobviously adjust the initial compression of the spring @d and hence thepressure resisting opening of the pilot valve.

There is provided a thermostatic control acting on the pilot valve. Itincludes a bulb 15 secured within the aforementioned T-connection I onthe brine outlet pipe I3. This bulb is connected by a tube 16,preferably capillary, to the interior of a collapsible bellows 11 thatis secured to the underside of a cap plate 18 attached to the casing 81of the pilot valve. A head 19 encloses the lower end of the bellows 11and has extending f therefrom an actuating pin 6@ of the knife-edgedFrom the description thus far, it may be seen that gas under pressureiiowing through the ports Si and SB to the upper side of the piston dimay force the piston downwardly against the combined action of thespring B2 and the evaporator pressure acting beneath the valve 33, toopen the main valve, when the quantity of gas owing in suiiicientlyexceeds that escaping by bleeding out.

The control of the. flow through, the port d5 is brought about by thepilot valve 20. This pilot valve has a. valve base 53 with an inlet adand an outlet 85, the former being connected with the line v2| and thelatter registering with the port 4B in'the cylinder head of the mainvalve. The vvalve base 53 is secured to the cylinder 33 by any suitablemeans, not shown.

The inlet 54 terminates in an annular groove 59 in the upper side of thevalve base 53. This groove has threaded and sealed therein a skirteddiaphragm holding member 51, with a diaphragm 58 secured between it anda ring 59 attached to the member l1 as by welding. A valve seat l0 is orof the point-contact type. .A cylinder 8| secured to thev underside ofthe cap` 18 inside the bellows is adapted to limit the collapse of thebellows by engagement therewith of the head 19. A suitable liquid thatexerts greater pressure upon temperature increase is put into the bulb.

The actuating point engages the outer end of a lever 85, the inner endof which is forked (Fig. 6) and straddles the hub on the head 63 oi thebuier plate stem 92. A pivot pin passes through the head 83 andthe'bifurcations of the lever 85 to provide pivotal connection betweenthe lever and the head. At the outer end oi the lever a leaf spring 91acts against a boss 89 extending upwardly from the bottom of the casing@l of the pilot valve. This spring maintains the outer end of the leverB5 against the pin 80. The spring dll causes the inner end of the leverd5 to move downwardly as far as is permitted by either the condition ofthe bellows or by the seating of the valve.

A movable fulcrum is provided for the lever 9E. This fulcrum consistsprimarily in a cylindrical pin secured to the upper surface of a hollowrectangular bracket 9| (Figs. 3 and 5) supported lon two slide rods 92threaded into the boss @s at one end, and passing through the casing t1main valve 83 permitting ed to be engaged by a suitable adjusting tool,

preferably the one that engages the head 88 on,

the adjusting screw 68. A cap |02 is threaded onto the boss 81 toprotect the head IOI. The

. packing 88 prevents outward movement of the Furthermore, if therefrigeration load changes.

' as by decreasing, the refrigeration capacity ci',

to the spring. The spring may be adjusted independently of theadjustment of the fulcrum.

The operation of the device is as :lollows:4 'I'he pilot valve isadapted to be opened when the pressure in the line I5, and hence in thepipe 2 I, attains a predetermined value, and whenA also the temperatureof the brine coming from the tank I I rises to apredetermined value..When this pressure in the pipe 2|, acting on the lower side of thediaphragm 58, is adequate to overcome the resistance of the buffer plate8|, which redsistance is a resultant of that produced by the spring 84and the bellows, the diaphragm will l be lifted. This valve need openonly a very slight amount to permit the flow of the pilot gas from theinlet 54 around the valve seat 60 to the outlet l5 and thence bypassagesl 45 and 46 to the upper side of the piston 4I. This pressure`will be suftlcient to overcome the combined force of the light spring42 and the force of the evaporator pressure acting upon valve 33, sothat the piston will be forced downwardly, opening the main valve 33 andpermitting the main body of the refrigerant gas to pass from the inletI8 through the valve to the outlet I8 and to the compressor.

When subsequently the pressure in the evaporator is reduced, as by areduction of refrigerating load, the pilot valve will be closed. Acertain amount of fluid under pressure will be enclosed within thepassages 55, 45 and 48, and also above the piston. Thisiluid, however,flows through the small bleeder port in the piston head, and

leuksV out through the' ported member 28 into the outlet I8, so thatthevmain valve thereupon closes under the iniluence of the spring 42.

It will be seen that the present-device comprises not only a pressureregulator with the desired functions thereof, but also a temperaturecontrol and a combination of temperature and pressure regulation',wherein the operation of a main control becomes dependent upon pressure,temperature, and a combination of them.

. To illustrate its uses,y there may be considered a refrigerationsystem subject to varying loads or refrigerating demands.

In a refrigerating system, there exists a'certain pressure in theevaporator coils, as coils I0. When this pressure, passing through theline 2|, acts upon the ydiaphragm 58 With whatever predetermined forceisnecessary to overcome the resultant force of the spring t4, thediaphragm the coils I0 at the aforementioned pressure, could becomeexcessive. It would reduce the tempera:

turev of. the medium being cooled, as the brine j lnfthe tank l I I, toa point where it might freeze, an obviously unfavorable condition. Inthe present mechanism, this cooling will iniluence 'the iluid. in the.4bulb `'15, reducing the pressure in the bellows TI, and in turn, byreducing the counter force of the bellows on the spring 64, increase theresultant pressure upon the diaphragm 58. Consequently a Vgreaterpressure is required underneath the diaphragm` to cause opening of the',

pilot valve and subsequent opening of the main valve. Thus the vpressurein coil I0 will rise after lowering of temperature of bulb 15. 'I'hishigher evaporator pressure in time reduces the coil capacity for thegiven load,thus preventing freezing for example. y

The foregoing illustration of one use of the device demonstrates that itis a combined temperature and pressure control.

The particular operating values are adjustable. 'I'he pressure of thespring 64 is determined by the setting of the screw 88. The counterpressure exerted by the bellows is determined4 by the setting ofthescrew |00, that adjusts the fulcrum 90 of the lever 85.

It will be observed that the maximum back pressure resisting opening ofthe pilot valve, is the full pressure of the spring 64, uninfiuenced bythe bellows. This value is the maximum critical pressure, and couldobtain, for instance, when the bulb is so cold that the bellows iscontracted as far as a point free of pressure upon the lever.

Upon increase of temperature of the bulb, the counterpressure of thebellows increases, and is applied against the spring with an eiect thatis a a function of the leverage, which in turn is determined by theposition of the fulcrum. Thus, if for a given setting of the fulcrum,there is 4a certain reduction of spring pressure per degree of will beforced off the'seat 60, opening the pilot Y valve, and as describedultimately opening the back to thecompressor. f

:dow of the refrigerant e 18, any reduction of this pressurel of asubstantial amount, will cause the pilot valve to close, and ultimatelythe main valve'also. 'I'he pilot vvalve maintains the desired minimumpressure.

It will be shown that the temperature control varies this minimumpressure in `response to temperature changes,

rise of temperature,l a decrease in the distance from the fulcrum to thepoint will produce an increase of reduction per .degree of rise.

partly vapor state during the operation, so that for any giventemperature it produces a determined pressure.

Usually it is desirable to operate at a range wherein the bellowsexertssome pressure at thel minimum operating temperature. If the rateof change or sensitivity is improper at such setting,

the fulcrum `may be adjusted in or out by the;

screw 94'.l This alters the pressure of operation at the particularpoint, because the pressure al-y ready exerted by the bellows isrendered more or lessjeiective. This change, then, while securing theproper rate oi.' change, or sensitivity, has al; iered the pressuresetting at the desired point.

v But the pressure setting may then be restored by e "adjustment of thescrew 66. l Thereafter, the' desired operating pressure and desired ratof change of pressure may be obtained.

It will be 'seen that the device has b'oth temperature and pressureacting upon a single valve,

'andthat this valve is formed by a single sealed element, the diaphragmrequiring no movable It may v. be noted that the liquid employed in thebulb or` bellows is one that assumes a partly liquid andV the line tocontrol flow therethrough, pressure responsive means to actuate the mainvalve including a fluid pressure line, a pilot valve in the fluidpressure line adapted tofbe actuated when the pressure attains acritical value, power means to move said pilot valve, said power meansbeing adjustable to change said critical value, and heat responsivemeans adapted to act in opposition to the power means to reduce saidcritical value upon rise in temperature where the refrigeration isproduced. K I 2. In a mechanism ci the kind described. a mai valve, apiston for actuating the valve, a cylinder for the piston, bleeder meansfrom the cylinder to the outlet' side of the main valve,l a fluidpressure line to the cylinder, a pilot valve in the Pressure line, saidpilot valve including 'a valve seat and a diaphragm, an inlet and anoutlet port on the same side oi the diaphragm but separated by the'valve seat, a casingl a plunger therein adapted to yforce the diaphragmonto the valve seat, said plunger being on the other side of thediaphragm,

an adjustable spring in the casing acting on the plunger, va bellows inthe casing having a bulb connected therewith, a lever between thebellows and the plunger, a fulcrum for the lever, said fulcrum beingmounted on a support member,

Y tracks on the casing to hold the support member,

a screw extending to the outside of the casing and adapted to displacethe support member along the tracks and adjust the fulcrum of the lever.

3. In a mechanism of the kind described for use in a refrigerationsystem including an evaporator for cooling a given medium and arefrigerant conducting line connected into the evaporator, thecombination of a valve in said line, pressure-responsive means includinga pressure element normally applying forceto close the valve and anopposing pressure-responsive means subiected to pressure in the line toeect opening oi the valve when said line pressure exceeds pressure ofthe pressure element, temperature responsive means operable in responseto increase in temperature of the medium being cooled to reduce theclosing force of the pressure element on the valve as said temperatureincreases, and means to adjust the amount of reduction of saidlast-named force, produced by the temperature as to be reluctant torespond to minor momentary in responseto pressure changes therein, thevalve being connected to the -expansible wall to be moved thereby, anadjustable spring acting in opposition to the expansible wall, saidspring urging the valve toward a rst position. means to stop the valvein said rst position, a lever connected to-the valve, an adjustablefulcrum for the lever, a heat responsive device including a membermovable in one direction in response to increase in temperature, saidlast-named member being adapted to abut the lever, and to pivot the samein a direction to oppose the spring, and being disconnected from theleverso as not to move the same when the temperature decreases.

5. In a refrigerating system having a fluid pressure line, a cut-offadapted to control fluid ow in said line, means subjected to fluidpressurev ahead of the cut-on and adapted to operate the cut-on in onedirection in response to increase in said fluid pressure, a rstyieldable force means, means applying the force of the rst force meansto oppose operation of the cut-ou by the fluid pressure, and mechanismincluding a second variable yleldable force means automatically operablein response to predetermined temperature conditions to produce varyingforces that are functions of said temperature conditions, said mechanismbeing adapted to apply a force in one direction only in opposition tothat produced by the first force means to reduce' the force tbm upon thecut-oil, said mechanism being incapable of producing a force in theother direction to increase the force of the nrst force producing meansin said other direction.

6. In a refrigerating system,a refrigerant control valve adspted tocontrol refrigerant ilow in a refrigerant. line in the system, pressurecontrolled mechanism to operate the valve comprising a movable meanssubjected to variable fluid pressure that increases as a function of aneed for increased refrigerant flow and movable in response thereto, andsaid mechanism also having a yieldable means acting to apply a force tosaid movable means to oppose the uid pressure thereon and close saidvalve, the pressure controlled mechanism being adapted to operate thevalve v /toward open'position in response to increase in responsivemeans per unit change in temperature.

sure chamber connected to the line ahead of the valve, an expansiblewall in the chamber movable the variable fluid pressure operating uponthe movable means, and to permit said yieldable means to close saidvalve upon reduction of said fluid pressure, additional meansautomatically op erable in response to predetermined temperatureconditions to move in opposite directions and to produce varying forcesthat are functions oi the said ,temperature conditions, and aconnection, including abutting parts, between said additional means andthe valve to apply force in one direction only to the valve when theadditional means moves in one direction, to override the force of one ofsaid means of the pressure controlled mechanism, and said additionalmeans being adapted to separate the abutting parts in said connectionupon movement in the opposite direction, said separation preventing theadditional means lfrom increasing the force oi the means it is adaptedto override. i

JOHN E. DUBE.

